Sparking plug with self-cleaning electrodes



. B. SCHERER'. SFARKING PLUG WITH SELF CLEANING ELECTRODES.

APPLICATION FILED MAR. 19, 1921. Patented Aug.'` 23, 1921.

UNITED STATES BENOIT SCHERM, 0F LA GARENNE-COLOMBES, FRANCE.

SPARKING YLUG- WITH SELF-CLEANING ELECTRODES.

Specication of Letters Patent. Patented Aug. 23, 1921.

Application led March 19, 1921. Serial No. 453,774.

To all lwhom it may concern.

Be it known that I, BnNo'r SCHERuR, a citizen of the Swiss Republic, and residing in La Garenne-Colombes, Seine, 28 Boulecomprise movable parts, and the said arrangement has for its object to perform a self cleaning of the parts upon which the sparks take place, thus favoring the operation of the spark-plug, and hence the operation of the motor.

It is known that in an internal combustion motor, alternatives of depression and compression take place respectively in every cylinder during the out-stroke and during the in stroke of the piston, so that in the compression chamber in the point where the sparking-plug is arranged, a depression takes place during one stroke, while a pressure of. gas takes place during the followin stroke, with an additional pressure at the time of the explosion, then a new depression at the time of the escaping of the gases.

I use such features for causing vibratory or other similar convenient movements of one electrode of the sparking-plug, or else of both electrodes, in order to perform the constant and automatic cleaning of the said electrodes.

In the accompanying drawing which shows some forms of construction .of a sparking plug according to the invention.

Figure 1 is a vertical axial section of a first constructional form,

Fig. 2 is a detail of the end of the plug on an enlarged scale, n

Fig. 3 is an end view.

Figs. 4 and 5 are an axial section and an end view of another constructional Aform respectively.

Figs. 6 and 7 are similar views of a modiication.

Referring to` Figs. 1- to 3, the sparkinglug comprises a body a, for instance metalic, intending to be screwed into the cylinder of the motor, not shown, and maintained in the said body for instance by means of a screw b with convenient tightening means in an insulating block c, for instance of porcelain, crossed by a metallic spindle d. The said spindle is provided at its upper part with a screw-threaded part which receives the leading-in-wire (not shown) and constitutes the central electrode of the sparking-plug. Such spindle has a lower part very strong in section e, which ends in a cylindric point f. Located at the lower part of the external body and inside the canal g, provided in the v said body, is a circular groove h, in which is arranged, with a convenient clearance a metallic annular disk i of a thickness less than the height of the groove, and provided at its central part, with a circular opening j for the passage of the point f of the central electrode d, e.

In the present constructional form, one of the electrodes being formed by the central spindle f, the other electrode is formed by the disk z' which is in permanent contact with the external body a, screwed into the motor cylinder. The sparks may, consequently, burst between the periphery of the point f of the central electrode and the periphery of the circular opening j of the said disk z.

During both the compression period, and the time the explosion is taking place, a violent pressing action is exerted against the disk t, which forces the same into the u per part of the groove, as shown in dotted ines in Fig. 2. During the period of escaping and of suction, the action of the iston brings back the disk into the position s own in full lines in Fig. 2. During that time, the gases contained in the internal room of the sparking-plug expand and force into the cylinder the particles of foreign bodies which have been broken up by these movements, thus freeing the sparking-plug from every particle tending to prevent its good operation.

In the constructional form of Figs. 4 and 5, mounted on the lower end of the metallic body a is a disk m comparatively thick, and provided at its center of an opening of a rather large diameter. The said disk is covered by a less thick plate n, maintained on the said disk m by means of rivets andfitted on the end of the central electrode f by a central opening having a diameter just suiiicient for permitting the said circular plate n to act as an electrode.

In the said constructional form, the movement of the gases causes the plate n to vibrate on its disk, such plate being iven the necessary elasticity by its little t ickness, which permits the self cleaning of the electrodes to be operated also in that case.

In Fig. 6, the external electrode is constituted by a disk o the thickness of which is going or lessening from the periphery to the center which is fitted at the lower part of the central body a and which comprises radial slots p of any number, the said slots providing points g which may be put 1n oscillation during the operation of the motor.

Instead of the arrangement described, the central movable electrode could be replaced, for instance by mounting onto the said electrode the disk i m or o, the periphery then could perform the movements descrlbed above which insure the constant cleaning of the sparking-plug and the keeping 1n a good state of operation of the surfaces between the sparks are to gush.

Both electrodes could also be rendered movable, for instance by providing each of them with a disk displaceable along the axis of the plug, care being taken that the distance between the said electrodies for the relative positions they may occupy, shall never be longer than the distance necessary for the normal operation of the plug.

The disk arranged inside the plug could have an upper inclined surface as shown in dotted lines in Figs. 2 and 4, in order to render easier the going out of the foreign particles.

Finally the said electrodes could be rendered movable in any Way other than that shown in the drawings, preventing that the said electrodes should keep a rigid, invariable relative position, in order to perform the self cleaning of the said electrodes during the operation of the motor under the effect of the alternative pressure and suction of the gases. The shape of the electrodes as well as the several parts of the plu may vary without departing from theprlneiple of the invention.

What I claim is:

l. A sparking plug for internal combustion engines, comprising a body having an annular internal groove in its lower portion, a metallic disk of less thickness than the width of the groove and loosely mounted therein, said disk being centrally apertured and forming an electrode, and a rod like electrode mounted in the body and having its end extending through the aperture in the disk electrode.

2. A sparking plug for internal combustion engine, comprising a body having an annular internal groove in its lower portion, a metallic disk of less thickness than the Width of the groove and loosely mounted therein, said disk being centrally apertured and forming an electrode, and a rod like electrode mounted in the body and having an enlarged and-tapering lower end extending through the aperture of the disk electrode.

In testimony I have hereunto set my hand at Paris (France) this 15th day February BENO'r soHERER. 

